Figure 3. Pcdh1 mRNA expression levels decrease after sub chronic smoke exposure.

(A) In the sub chronic smoke exposure model, mice were exposed to 1 and 3 cigarettes or air at day 1, followed by 5 cigarettes at day 2–5 or air. 2 h after the last cigarette both smoke and air exposed mice were sacrificed. Neutrophils in the bronchoalveolar lavage fluid, and airway hyperresponsiveness to methacholine were determined. Error bars show Standard Deviation. Two independent experiments are shown individually. (B) Pcdh1 exon 1–2 and 3–4 transcript levels were determined in lungs of air exposed (open symbols) and smoke exposed (closed symbols) mice. (C) Pcdh1 protein levels were determined by western blot of lung homogenate of air (control) and smoke exposed mice. Pcdh1 isoform 1 (arrow indicates the specific band; EP78-antibody), full-length isoform 2 (EP76-antibody) and 50 kD (EP76-antibody) levels are shown, with β-actin as loading control. (D) Densitometric quantification of Pcdh1 expression levels of full-length isoform 1 and 2, and the 50 kD fragment, relative to β-actin. Cig = cigarette; † = time-point at which mice are sacrificed.